Electronic typewriters commonly use a printing ribbon that is wider than the combined height of several characters, and a ribbon lifting mechanism operates to lift the ribbon to the printing position in such a manner that the ribbon lifting amount is changed in two or three steps. In this way, a number of rows of characters or symbols can be printed with a ribbon of limited length. In a typewriter using such a multi-track type printing ribbon, the distance that the ribbon is stepped in the longitudinal direction is constant at all times and fails to take into consideration the actual widths of the characters just printed.
Accordingly, the ribbon stepping amount must be set so that even when the widest characters or symbols, for instance the under-line (--) are successively printed in a row on the ribbon, the print marks on the ribbon will not overlap each other. Therefore, since the ribbon is limited in length, the number of characters that may be printed before discarding a ribbon is unnecessarily decreased, and ribbon consumption is increased.
On the other hand, since the ribbon is in the form of a thin tape, when the ribbon is stepped while being wound, it is liable to be slackened. This makes it difficult to increase the ribbon stepping speed even though the print hammer or the carriage can be operated at a high speed. Therefore, if the ribbon stepping amount is large, then the printing speed of the typewriter is adversely affected. Accordingly, it has not been possible to increase the printing speed beyond certain limits set by the ribbon advance mechanism.